Since Java 21, wrapper classes have played an increasingly sophisticated role in Java’s type system. Here’s everything you ...

Classes and objects in Java must be initialized before they are used. You’ve previously learned that class fields are initialized to default values when classes are loaded, and that objects are ...

Sealed classes make Java an even more powerful and expressive language and set the stage for even more sophisticated techniques such as pattern matching, which we'll explore in a subsequent article. A ...

JDO provides transparent persistence for Plain Old Java Objects (POJO) [FOWLER] classes, which means that we can develop and test the domain model without a database. JDO applications can be run ...